A taskbar icon refers to a small picture or symbol that represents an open program or application on the taskbar, which is usually located at the bottom of the computer screen. Full definition
Pinned sites not only get their own taskbar icons, but their favicon is also used where a browser logo would normally be, in the upper left corner of the window. (pcmag.com)
In the settings window, turn on the «Use small taskbar icons» option. (howtogeek.com)
Up to three people can be pinned as taskbar icons, and the rest will appear in the panel that pops up after you click the People button. (howtogeek.com)